/*
 * Created on 1 Nov 2006
 * Created by Paul Gardner
 * Copyright (C) Azureus Software, Inc, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

package com.aelitis.azureus.core.networkmanager.admin.impl;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;
import java.util.StringTokenizer;

import org.gudy.azureus2.core3.internat.MessageText;
import org.gudy.azureus2.core3.util.AESemaphore;
import org.gudy.azureus2.core3.util.Debug;
import org.gudy.azureus2.core3.util.SystemTime;

import com.aelitis.azureus.core.networkmanager.ProtocolEndpoint;
import com.aelitis.azureus.core.networkmanager.ProtocolEndpointFactory;
import com.aelitis.azureus.core.networkmanager.VirtualChannelSelector;
import com.aelitis.azureus.core.networkmanager.admin.NetworkAdminException;
import com.aelitis.azureus.core.networkmanager.admin.NetworkAdminHTTPProxy;
import com.aelitis.azureus.core.networkmanager.impl.tcp.ProtocolEndpointTCP;
import com.aelitis.azureus.core.networkmanager.impl.tcp.TCPConnectionManager;
import com.aelitis.azureus.core.networkmanager.impl.tcp.TCPNetworkManager;
import com.aelitis.azureus.core.networkmanager.impl.tcp.TCPTransportHelperFilterFactory;
import com.aelitis.azureus.core.networkmanager.impl.tcp.TCPTransportImpl;
import com.aelitis.azureus.core.versioncheck.VersionCheckClient;

public class NetworkAdminHTTPProxyImpl implements NetworkAdminHTTPProxy {
    private static final String NL = "\015\012";

    private final String TARGET_HOST = VersionCheckClient.HTTP_SERVER_ADDRESS_V4;
    private final int TARGET_PORT = VersionCheckClient.HTTP_SERVER_PORT;

    private String http_host;
    private String http_port;
    private String https_host;
    private String https_port;

    private String user;
    private String password;

    private String[] non_proxy_hosts;

    protected NetworkAdminHTTPProxyImpl() {
        http_host = System.getProperty("http.proxyHost", "").trim();
        http_port = System.getProperty("http.proxyPort", "").trim();
        https_host = System.getProperty("https.proxyHost", "").trim();
        https_port = System.getProperty("https.proxyPort", "").trim();

        user = System.getProperty("http.proxyUser", "").trim();
        password = System.getProperty("http.proxyPassword", "").trim();

        String nph = System.getProperty("http.nonProxyHosts", "").trim();

        StringTokenizer tok = new StringTokenizer(nph, "|");

        non_proxy_hosts = new String[tok.countTokens()];

        int pos = 0;

        while (tok.hasMoreTokens()) {

            non_proxy_hosts[pos++] = tok.nextToken();
        }
    }

    public String getName() {
        String res = "";

        if (http_host.length() > 0) {

            res = "http=" + http_host + ":" + http_port;
        }

        if (https_host.length() > 0) {

            res += (res.length() == 0 ? "" : ", ") + "https=" + https_host + ":" + https_port;
        }

        return (res);
    }

    protected boolean isConfigured() {
        return (http_host.length() > 0 || https_host.length() > 0);
    }

    public String getHTTPHost() {
        return (http_host);
    }

    public String getHTTPPort() {
        return (http_port);
    }

    public String getHTTPSHost() {
        return (https_host);
    }

    public String getHTTPSPort() {
        return (https_port);
    }

    public String getUser() {
        return (user);
    }

    public String[] getNonProxyHosts() {
        return (non_proxy_hosts);
    }

    public String getString() {
        String res = getName();

        if (user.length() > 0) {

            res += " [auth=" + user + "]";
        }

        try {

            NetworkAdminHTTPProxy.Details details = getDetails();

            res += " server=" + details.getServerName();
            res += ", response=" + details.getResponse();
            res += ", auth=" + details.getAuthenticationType();

        } catch (NetworkAdminException e) {

            res += " failed to query proxy - " + e.getLocalizedMessage();
        }

        return (res);
    }

    public Details getDetails()

    throws NetworkAdminException {
        final int RES_CONNECT_FAILED = 0;
        final int RES_PROXY_FAILED = 1;
        final int RES_OK = 3;

        final AESemaphore sem = new AESemaphore("NetworkAdminSocksProxy:test");

        final int[] result = { RES_CONNECT_FAILED };

        final NetworkAdminException[] error = { null };
        final ProxyDetails[] details = { null };

        try {
            InetSocketAddress socks_address = new InetSocketAddress(InetAddress.getByName(http_host), Integer.parseInt(http_port));

            final InetSocketAddress target_address = new InetSocketAddress(TARGET_HOST, TARGET_PORT);

            TCPConnectionManager.ConnectListener connect_listener = new TCPConnectionManager.ConnectListener() {
                public int connectAttemptStarted(int default_connect_timeout) {
                    return (default_connect_timeout);
                }

                public void connectSuccess(SocketChannel channel) {
                    final TCPTransportImpl transport =
                            new TCPTransportImpl((ProtocolEndpointTCP) ProtocolEndpointFactory.createEndpoint(ProtocolEndpoint.PROTOCOL_TCP,
                                    target_address), false, false, null);

                    transport.setFilter(TCPTransportHelperFilterFactory.createTransparentFilter(channel));

                    final long start_time = SystemTime.getCurrentTime();

                    try {
                        String get_str = VersionCheckClient.getSingleton().getHTTPGetString(true, false);

                        ByteBuffer request = ByteBuffer.wrap(get_str.getBytes());

                        while (request.hasRemaining()) {

                            if (transport.write(new ByteBuffer[] { request }, 0, 1) < 1) {

                                if (SystemTime.getCurrentTime() - start_time > 30 * 1000) {

                                    String error = "proxy handshake message send timed out after 30sec";

                                    Debug.out(error);

                                    throw new IOException(error);
                                }

                                try {
                                    Thread.sleep(50);

                                } catch (Throwable t) {

                                    t.printStackTrace();
                                }
                            }
                        }

                        TCPNetworkManager.getSingleton().getReadSelector().register(transport.getSocketChannel(),
                                new VirtualChannelSelector.VirtualSelectorListener() {
                                    private byte[] reply_buffer = new byte[8192];

                                    private ByteBuffer reply = ByteBuffer.wrap(reply_buffer);

                                    public boolean selectSuccess(VirtualChannelSelector selector, SocketChannel sc, Object attachment) {
                                        try {
                                            if (SystemTime.getCurrentTime() - start_time > 30 * 1000) {

                                                throw (new Exception("Timeout"));
                                            }

                                            long len = transport.read(new ByteBuffer[] { reply }, 0, 1);

                                            if (len <= 0) {

                                                return (false);
                                            }

                                            String str = new String(reply_buffer, 0, reply.position());

                                            if (str.indexOf(NL + NL) != -1) {

                                                System.out.println(str);

                                                String server_name = "unknown";
                                                String auth = "none";
                                                String response = "unknown";

                                                StringTokenizer tok = new StringTokenizer(str, "\n");

                                                int line_num = 0;

                                                while (tok.hasMoreTokens()) {

                                                    String token = tok.nextToken().trim();

                                                    if (token.length() == 0) {

                                                        continue;
                                                    }

                                                    line_num++;

                                                    if (line_num == 1) {

                                                        int pos = token.indexOf(' ');

                                                        if (pos != -1) {

                                                            response = token.substring(pos + 1).trim();
                                                        }
                                                    } else {

                                                        int pos = token.indexOf(':');

                                                        if (pos != -1) {

                                                            String lhs = token.substring(0, pos).trim().toLowerCase(MessageText.LOCALE_ENGLISH);
                                                            String rhs = token.substring(pos + 1).trim();

                                                            if (lhs.equals("server")) {

                                                                if (!response.startsWith("200")) {

                                                                    server_name = rhs;
                                                                }
                                                            } else if (lhs.equals("via")) {

                                                                server_name = rhs;

                                                                int p = server_name.indexOf(' ');

                                                                if (p != -1) {

                                                                    server_name = server_name.substring(p + 1).trim();
                                                                }

                                                            } else if (lhs.equals("proxy-authenticate")) {

                                                                auth = rhs;
                                                            }
                                                        }
                                                    }
                                                }

                                                details[0] = new ProxyDetails(server_name, response, auth);

                                                transport.close("Done");

                                                result[0] = RES_OK;

                                                sem.release();

                                            } else {

                                                TCPNetworkManager.getSingleton().getReadSelector().resumeSelects(transport.getSocketChannel());
                                            }

                                            return (true);

                                        } catch (Throwable t) {

                                            return false;
                                        }
                                    }

                                    public void selectFailure(VirtualChannelSelector selector, SocketChannel sc, Object attachment, Throwable msg) {
                                        result[0] = RES_PROXY_FAILED;
                                        error[0] = new NetworkAdminException("Proxy error", msg);

                                        transport.close("Proxy error");

                                        sem.release();
                                    }
                                }, null);

                    } catch (Throwable t) {

                        result[0] = RES_PROXY_FAILED;
                        error[0] = new NetworkAdminException("Proxy connect failed", t);

                        sem.release();
                    }
                }

                public void connectFailure(Throwable failure_msg) {
                    result[0] = RES_CONNECT_FAILED;
                    error[0] = new NetworkAdminException("Connect failed", failure_msg);

                    sem.release();
                }
            };

            TCPNetworkManager.getSingleton().getConnectDisconnectManager().requestNewConnection(socks_address, connect_listener,
                    ProtocolEndpoint.CONNECT_PRIORITY_MEDIUM);

        } catch (Throwable e) {

            result[0] = RES_CONNECT_FAILED;
            error[0] = new NetworkAdminException("Connect failed", e);

            sem.release();
        }

        if (!sem.reserve(10000)) {

            result[0] = RES_CONNECT_FAILED;
            error[0] = new NetworkAdminException("Connect timeout");
        }

        if (result[0] == RES_OK) {

            return (details[0]);
        }

        throw (error[0]);
    }

    protected class ProxyDetails implements Details {
        private String name;
        private String response;
        private String auth_type;

        protected ProxyDetails(String _name, String _response, String _auth_type) {
            name = _name;
            response = _response;
            auth_type = _auth_type;
        }

        public String getServerName() {
            return (name);
        }

        public String getResponse() {
            return (response);
        }

        public String getAuthenticationType() {
            return (auth_type);
        }
    }
}
